It is 60 years since JD Salinger invented teenage anxiety. The voice of the fragile Glass family and Holden Caulfield - damaged, precocious, confessional, self-obsessed, wearing irony against the emptiness of things - persists as about the most influential rhetoric of our lives: you can't imagine Morrissey or MySpace without it. It is, therefore, remarkable how much genuine life and surprise Joe Dunthorne brings to it in his perfectly pitched debut novel Submarine.

Dunthorne, who is 26, and wrote this book on the creative writing course at East Anglia, transplants The Catcher in the Rye to south Wales, somewhere between Swansea, where he grew up, and Port Talbot. Oliver Tate is 15, despairingly obsessed with his virginity, in love with his own cleverness, and wildly trying to save his parents' marriage. He is, in common with many 15-year-olds, full of tremendous moral self-righteousness about adult failings and in possession of only half the facts.

Dunthorne provides him with a manner that captures exactly his addictive mix of innocence and experience. Oliver introduces himself like this: 'I recently discovered that my mother had been typing the names of as-yet-uninvented mental conditions into Yahoo's search engine: "delusion syndrome teenage", "over-active imagination problem", "holistic behavioural stabilisers".' He resolves to help his mother toward a diagnosis of Cotard's syndrome, a branch of autism where people believe they are dead, by dropping phrases like: 'My body has been replaced by a shell' and: 'My organs are made of stone' randomly into his conversation. Meanwhile, he pursues avid detective work into his parents' sex life.

Oliver is way too smart for his own good ('If a graphologist were to examine my handwriting, they would note that I am creative, sensitive and destined for a modicum of success'); he is led by his peers but chastened by guilt: he can't resist being part of the gang that steals a fat girl's diary, but then, when she changes schools as a result, he writes her a self-help manual with tips on how to avoid bullying: 'You must be willing to transform any facet of your personality to fit in.'

If there is a danger of Adrian Mole in some of this, Dunthorne sidesteps it by having Oliver write a pastiche Mole diary 'All the people I have ever kissed: Arwen Slade: I kissed her on the bus on the way to Dan yr Ogof. She had just eaten half a bag of flying saucers. Her saliva tasted like coins.' And there is enough bleakness and wit to counter the childlike one-liners.

Even so, Oliver can't resist them. 'Mary Pugh wears her goggles over her glasses: six eyes,' he observes of a classmate in the chemistry lab; or, of his father in a crisis: '"Nnngh," he grunts while getting his balance. This is no time for vowels.' When it comes to first sex, Oliver's curiosity properly knows no limits. 'You snog like a dentist,' his girlfriend observes. Most ventriloquism of teenage years doesn't capture the giggling fits that get you through the routine boredom of school and home, but Dunthorne can, at times, make you laugh like you did during double physics on a wet Wednesday afternoon.